1. Field
The present invention relates generally to digital television and broadcast systems and, more specifically, to using event notifications for controlling the recording of digital television programs.
2. Description
The broadcasting industry is expanding into digital broadcast technologies that promise new features, higher resolution video and audio, and other technological enhancements. Digital television (DTV) broadcasting provides at least several advancements in broadcast content enhancement. One type of content enhancement is the addition of supplemental information to the regular broadcast transmission. Supplemental information can take many forms, such as Hypertext Markup Language (HMTL), meta-data, and other information carrying data structures. Enhanced or interactive television incorporates the supplemental information into the viewing experience through interactive displays, links to web pages on the Internet, and other features.
The Advanced Television Enhancement Forum (ATVEF) (www.atvef.org) is a cross-industry alliance of companies representing broadcast and cable networks, television transports, the consumer electronics industry, and the personal computer (PC) industry. ATVEF has defined protocols for HTML-based enhanced television, which allow content creators to deliver enhanced programming over all forms of transport (analog, digital, cable, Internet and satellite) to intelligent receivers. ATVEF has published the Enhanced Content Specification, version 1.1, revision 26, 1998-2000 (hereinafter referred to as the xe2x80x9cATVEF Specificationxe2x80x9d) to promote consistent methods for providing enhancements in both analog and digital broadcasting systems. The ATVEF Specification provides a standard for delivering interactive TV experiences that can be authored once using a variety of tools and deployed to a variety of TV, set top box, and PC-based receivers. The ATVEF Specification specifies content formats and delivery mechanisms for the transmission and processing of triggers, resources, announcements, and content that are associated with an enhanced TV transmission. Such enhancements are often suitable for use by a computer system (such as a PC), connected to the Internet or other network. For example, one type of supplemental information is a Universal Resource Locator (URL) to a TV network""s web site where additional information relating to a TV program may be found. In one scenario for enhanced TV viewing, a viewer may watch a TV program and be notified of a related web site. The viewer may then obtain one or more web pages from the identified web site and display them either on the TV screen or on another display concurrently with viewing the TV program.
Recording of TV programs using analog means is widespread. Video cassette recorders (VCRs) are used by millions of people to record their favorite TV programs. Recently, devices for recording of TV programs using digital means have been introduced. These devices store selected TV programs on a storage medium such as a computer hard drive. Other TV recording technologies include products that automatically find, schedule and record favorite shows to a VCR. All of these devices, however, allow only time-driven recording. That is, the viewer typically sets the channel number, start time, and duration of the program (or end time), and the device records the program broadcast on the selected channel during a specified time period. Control over what is to be recorded is determined by the starting and ending times of the programs.
In contrast, it is desirable in some instances to automatically record only certain fragments or segments of interest in a program. For example, a viewer may want to record the weather forecast from the local news, or a movie without commercials, or scoring plays in a football game. Furthermore, in many cases, the viewer may not know exactly when the program segment is being broadcast. If the viewer sets up the recording of an entire program when only a portion of the program is of interest, video storage is wasted. Additionally, finding the segment of interest in the entire recorded program at a later point in time may be time consuming and difficult.